Question

ребят пж помогите 2,4,6 задания
плиз срочно нужно

Answer 1

1)

$- 7(2 - 3x) = 56 \\ - 14 + 21x = 56 \\ 21x = 70 \\ x = \frac{70}{21} = 3 \frac{7}{21} = 3 \frac{1}{3}$

2)

$0.8(4x + 5) = - 3.2 \\ 3.2x + 4 = - 3.2 \\ 3.2x = - 7.2 \\ x = 2.25$

3)

$- 2.4(7 - 9y) = - 48 \\ - 16.8 + 21.6y = - 48 \\ 21.6y = - 31.2 \\ y = - \frac{312}{216} = - 1 \frac{96}{216} = - 1 \frac{4}{9}$

4)

$(5 + 7a) \times 15 = 12 \\ 75 + 105a = 12 \\ 105a = - 63 \\ a = - \frac{63}{105} = - \frac{3}{5} = - 0.6$

5)

$0.6(2x + 1) = - 1.8(3x - 4) \\ 1.2x + 0.6 = - 5.4x + 7.2 \\ 6.6x = 6.6 \\ x = 1$

6)

$- 1.4(x - 6) = 7(4x + 1.2) \\ - 1.4x + 8.4 = 28x + 8.4 \\ 26.6x = 0 \\ x = 0$

7)

$- 40.5(6x + 1) = - 45(2x + 2.6) \\ - 243x - 40.5 = - 90x - 117 \\ - 153x = - 76.5 \\ x = 0.5$

8)

$2.6(0.4x - 1.4) = - 3.9(1.2x - 0.9) \\ 1.04x - 3.64 = - 4.68x + 3.51 \\ 5.72x = 7.15 \\ x = 1.25$